RESUMOO molusco Anomalocardia brasiliana é sensível a variações ambientais, com alta mortalidade devido às chuvas. Em Pernambuco, dentre as espécies de maior produção de pescado, o marisco é o que mais se destaca, com grande importância econômica. Objetivou-se com o estudo avaliar a população remanescente de A. brasiliana da praia de Mangue Seco, durante o período chuvoso e na época de seca, após a captura pelos pescadores e em três momentos de amostragens. Na avaliação dos dados foram considerados três fatores: Período, Tipo de extração e Momento da amostragem. As variáveis analisadas foram comprimento total e número total de animais amostrados. O estudo foi realizado no mês de agosto de 2009, após o período chuvoso, e no mês de janeiro de 2010, época de seca na região nordeste do Brasil. A quantidade de animais capturados com tamanho recomendado para pesca (> 20 mm) foi superior a 80% no mês de agosto e inferior a 20 % em janeiro. Não foi observada diferença significativa entre os tamanhos dos animais coletados. O período chuvoso na região nordeste do Brasil exerce influência na população de A. brasiliana, provocando redução no número de mariscos, contudo, é nesta época do ano que há maior frequência de indivíduos adultos.Palavras-chave: captura, marisco, métodos de pesca, pescadores Effect of the rainy season on the extraction of bivalve mollusc Anomalocardia brasiliana (Gmelin, 1791) ABSTRACTThe mollusc Anomalocardia brasiliana is sensitive to environmental variations with high mortality due to rains. In the state of Pernambuco, among the species of larger fisheries production, this clam has great economic importance. The study aimed to evaluate the remaining population of A. brasiliana of beach Mangue Seco, during the rainy and dry season, after the capture by fishermen and three moments of sampling. In evaluation of data three factors were considered: period; type of extraction and moment of sampling. Response variables analysed were total length and total number of animals sampled. The study was conducted in August 2009, after the rainy season, and in January 2010, the dry season in northeastern Brazil. The amount of captured animals with recommended size for fishing (> 20 mm) was above 80% in August, and below 20% in January. There was no significant difference between the sizes of the animals collected. The rainy season in northeastern Brazil influences the population of A. brasiliana, causing reduction in the number of clams, however, at this time of year there is a higher frequency of adults.

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Anomalocardia brasiliana post-larvae were cultured for 28 days to evaluate the effect of stocking density on their growth and survival rate. Three stocking densities were tested 40, 80 and 160 post-larvae cm-2, in experimental units (2-L) with static cultivation system and total water renewal at each 48 hours. The experimental design was completely randomized with three treatments and three repetitions each. Stocking density of 40 post-larvae cm-2 reached 1 mm length within 24 days, while only 18% of the post-larvae at density of 80 post-larvae cm-2 reached 1 mm length in the same time. The density of 40 post-larvae cm-2 had the highest specific growth rate, 4.98±0.08% day-1. The survival rates of post-larvae at lower densities were significantly higher (53.24±4.60% and 52.95±3.32%, on 40 and 80 post-larvae cm-2, respectively) compared to higher stocking density (31.54±0.70%). In the cultivation of A. brasiliana post-larvae, stocking density must be managed during growth. The density of 160 post-larvae cm-2 can only be used until the post-larvae reach 600μm in length, then they should be at 40 post-larvae cm-2 density to keep the maximum daily growth rate.